Communicating control information in mobile communication system

ABSTRACT

The present invention relates to communicating control information in a mobile communication system, wherein the control information of a mobile terminal for scheduling an uplink channel may be notified to a network more quickly with less power. The present invention comprises transmitting a data block on a first physical channel, wherein the data block comprises control information, and transmitting an indicator having a specific value on a second physical channel for indicating the transmission of the control information on the first physical channel.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.11/429,114, filed on May 4, 2006, now U.S. Pat. No. 8,665,836, whichclaims the benefit of earlier filing date and right of priority toKorean Application No. P2005-0038143, filed on May 6, 2005, the contentsof which are hereby incorporated by reference herein in their entirety.

FIELD OF THE INVENTION

The present invention relates to communicating control information in amobile communication system, wherein the control information of a mobileterminal for scheduling an uplink channel may be notified to a networkmore quickly with less power.

BACKGROUND OF THE INVENTION

FIG. 1 is a block diagram of a network structure of a universal mobiletelecommunications system (UMTS) of a 3GPP asynchronous IMT-2000 system.Referring to FIG. 1, a UMTS mainly includes a user equipment (UE), aUMTS terrestrial radio access network (UTRAN), and a core network (CN).

The UTRAN includes at least one radio network sub-system (hereinafterabbreviated RNS). The RNS includes one radio network controller (RNC)and at least one base station (Node B) managed by the RNC. At least oneor more cells exist in one Node B.

FIG. 2 is an architectural diagram of a radio interface protocol betweenthe UE (user equipment) and the UTRAN (UMTS terrestrial radio accessnetwork). Referring to FIG. 2, a radio interface protocol verticallyincludes a physical layer, a data link layer, and a network layer.Horizontally, the radio interface protocol includes a user plane fordata information transfer and a control plane for signaling transfer.

The protocol layers in FIG. 2 can be divided into a first layer (L1), asecond layer (L2), and a third layer (L3) such as the three lower layersof an open system interconnection (OSI) standard model widely known inthe art. The respective layers in FIG. 2 are explained as follows.

A physical layer (PHY) is the first layer and offers an informationtransfer service to an upper layer using a physical channel. Thephysical layer (PHY) is connected to a medium access control (MAC) layerlocated above the physical layer PHY via a transport channel. Data istransferred between the MAC layer and the PHY layer via the transportchannel. Moreover, data is transferred between different physicallayers, and more particularly, between a physical layer of atransmitting side and a physical layer of a receiving side via thephysical channel.

The MAC layer of the second layer offers a service to a radio linkcontrol (RLC) layer located above the MAC layer via a logical channel.The RLC layer supports reliable data transfer and is operative insegmentation and concatenation of RLC service data units sent down froman upper layer. Hereinafter, the service data unit will be abbreviatedSDU.

A broadcast/multicast control (BMC) layer schedules a cell broadcastmessage (CB message) delivered from a core network and facilitatesbroadcasting the message to UEs existing in a specific cell(s). From aUTRAN perspective, the CB message is delivered from a higher layer andis additionally provided with information such as a message ID, a serialnumber, and a coding scheme, for example. The CB message is delivered toan RLC layer in a BMC message format, and is then delivered to a MAClayer via a logical channel, such as a common traffic channel (CTCH).The logical channel CTCH is mapped to a transport channel, such as aforward access channel (FACH) and a physical channel, such as asecondary common control physical channel (S-CCPCH).

A packet data convergence protocol (PDCP) layer lies above the RLC layerand enables data, which is transferred via a network protocol such as anIPv4 or IPv6, to be efficiently transferred on a radio interface havinga relatively small bandwidth. For this, the PDCP layer facilitatesreducing unnecessary control information used by a wired network. Thisfunction is called header compression, for which a header compressionscheme such as RFC2507 or RFC3095 (robust header compression: ROHC),defined by the Internet Engineering Task Force (IETF), can be used. Inthese schemes, only information mandatory for a header part of data istransferred, thereby reducing data volume to be transferred bytransferring a smaller amount of control information.

A radio resource control (RRC) layer is located on a lowest part of thethird layer. The RRC layer is defined in the control plane only and isassociated with the configuration, reconfiguration and release of radiobearers (RBs) for controlling the logical, transport and physicalchannels. In this case, the RB is a service offered to the second layerfor a data transfer between the UE and the UTRAN. Specifically, the RBis a logical path provided by Layer 1 and Layer 2 of a radio protocolfor the data delivery between the UE and the UTRAN The configuration ofthe RB is a process of regulating characteristics of protocol layers andchannels necessary for offering a specific service and a process ofsetting their specific parameters and operational methods, respectively.

The RRC layer broadcasts system information via a broadcast controlchannel (BCCH). System information for one cell is broadcast to the UEvia a system information block (SIB) format. In case that the systeminformation is changed, the UTRAN transmits BCCH modificationinformation to the UE via a paging channel (PCH) or a forward accesschannel (FACH) to induce the UE to receive the latest systeminformation.

According to the recent demand for high speed and capacity increment ofuplink data in a wireless mobile communication system, a high-speedpacket communication system in uplink wherein a user equipment transmitsdata to a base station is actively discussed. Enhanced uplink dedicatedchannel (E-DCH) technology is representatively discussed in the 3GPPWCDMA wireless mobile communication system. In the E-DCH technology,uplink packet scheduling by a base station (Node B), HARQ (Hybrid ARQ)in a physical layer and the like are introduced into the conventional3GPP WCDMA uplink DCH (dedicated channel) to enhance efficiency ofuplink.

FIG. 3 is a diagram of a structural example of DCH and E-DCH. Referringto FIG. 3, both DCH and E-DCH are transport channels that can bededicatedly used by one user equipment (UE). In particular, the E-DCH isused by a user equipment to transfer data to a UTRAN in uplink. Comparedto the DCH, the E-DCH can transfer uplink data faster than the DCH. Totransfer data at high speed, the E-DCH adopts a technique such as hybridautomatic repeat request (HARQ), adaptive modulation and coding (AMC)and scheduling controlled by a Node B, for example.

For E-DCH, the Node B transfers to the UE downlink control informationfor controlling the UE's E-DCH transfer. The downlink controlinformation includes response information (ACK/NACK) for HARQ, channelquality information for AMC, E-DCH transport rate assignmentinformation, E-DCH transport start time and transport time intervalassignment information, and transport block size information, forexample. Meanwhile, the UE transfers uplink control information to theNode B. The uplink control information includes E-DCH rate requestinformation for Node B controlled scheduling, UE buffer statusinformation, and UE power status information, for example. The uplinkand downlink control information for E-DCH is transferred via a physicalcontrol channel such as an enhanced dedicated physical control channel(E-DPCCH).

A MAC-d flow is defined between a MAC-d sublayer and a MAC-e sublayerfor E-DCH. In this case, a dedicated logical channel is mapped to theMAC-d flow. The MAC-d flow is mapped to a transport channel E-DCH, andthe E-DCH is mapped to another physical channel E-DPDCH (enhanceddedicated physical data channel). On the other hand, the dedicatedlogical channel can be directly mapped to DCH. In this case, thetransport channel DCH is mapped to a dedicated physical data channel(DPDCH). The MAC-d sublayer in FIG. 3 manages the DCH (dedicatedchannel) as a dedicated transport channel for a specific user equipment,while the MAC-e sublayer manages the E-DCH (enhanced dedicated channel)as a transport channel used in transferring fast data in uplink.

A MAC-d sublayer of a transmitting side configures a MAC-d protocol dataunit (PDU) from a MAC-d service data unit (SDU) delivered from an upperlayer, i.e., an RLC layer. A MAC-d sublayer of a receiving sidefacilitates recovery of the MAC-d SDU from the MAC-d PDU received from alower layer and delivers the recovered MAC-d SDU to an upper layer. Indoing so, the MAC-d exchanges the MAC-d PDU with a MAC-e sublayer via aMAC-d flow or exchanges the MAC-d PDU with a physical layer via the DCH.The MAC-d sublayer of the receiving side recovers the MAC-d PDU using aMAC-d header attached to the MAC-d PDU prior to delivering the recoveredMAC-d SDU to an upper layer.

A MAC-e sublayer of a transmitting side configures a MAC-e PDU from aMAC-e SDU corresponding to a MAC-d PDU delivered from an upper layer,i.e., a MAC-d sublayer. The MAC-e sublayer of a receiving sidefacilitates recovery of the MAC-e SDU from the MAC-e PDU received from alower layer, i.e., a physical layer and delivers the recovered MAC-e SDUto a higher layer. In doing so, the MAC-e exchanges the MAC-e PDU withthe physical layer via the E-DCH. The MAC-e sublayer of the receivingside recovers the MAC-e SDU using a MAC-e header attached to the MAC-ePDU prior to delivering the recovered MAC-e SDU to a higher layer.

FIG. 4 is a diagram of a protocol for E-DCH. Referring to FIG. 4, aMAC-e sublayer supporting E-DCH exists below a MAC-d sublayer of aUTRAN. Furthermore, a MAC-e sublayer supporting E-DCH exists below aMAC-d sublayer of a UE. The MAC-e sublayer of the UTRAN is located at aNode B. The MAC-e sublayer exists in each UE. On the other hand, theMAC-d sublayer of the UTRAN is located at a serving radio networkcontroller (SRNC) in charge of managing a corresponding UE. The MAC-dsublayer exists in each UE.

Control information transmission for E-DCH is explained as follows.First of all, a scheduler exists at a Node B for E-DCH. The schedulerfacilitates the allocation of an optimal radio resource to each UEexisting within one cell to raise transmission efficiency of data in anuplink transfer at a base station from all UEs within each cell. Inparticular, more radio resources are allocated to a UE having a goodchannel status in one cell to enable the corresponding UE to transmitmore data. Less radio resources are allocated to a UE having a poorchannel status to prevent the corresponding UE from transmittinginterference signals over an uplink radio channel.

When allocating radio resources to the corresponding UE, the schedulerdoes not only consider a radio channel status of a UE. The scheduleralso requires control information from UEs. For example, the controlinformation includes a power quantity the UE can use for E-DCH or aquantity of data the UE attempts to transmit. Namely, even if the UE hasa better channel status, if there is no spare power the UE can use forE-DCH, or if there is no data the UE will transmit in an uplinkdirection, a radio resource should not be allocated to the UE. In otherwords, the scheduler can raise the efficiency of radio resource usewithin one cell only if a radio resource is allocated to a UE having aspare power for E-DCH and data to be transmitted in the uplink transfer.

Accordingly, a UE should send control information to a scheduler of aNode B. The control information can be transmitted in various ways. Forinstance, a scheduler of a Node B can instruct a UE to report that datato be transmitted in uplink exceeds a specific value or to periodicallysend control information to the Node B itself.

In case a radio resource is allocated to a UE from a scheduler of a NodeB, the UE configures a MAC-e PDU within the allocated radio resource andthen transmits the MAC-e PDU to a base station via E-DCH. In particular,if data to be transmitted exists, a UE sends control information to aNode B to inform the Node B that there is data to be transmitted by theUE. A scheduler of the Node B then sends information indicating that aradio resource allocation will be made to the UE based on the controlinformation been sent by the UE. In this case, the informationindicating the radio resource allocation means a maximum value of powerthe UE can transmit in uplink, a ratio for a reference channel, etc. TheUE configures the MAC-e PDU within a permitted range based on theinformation indicating the radio resource allocation and transmits theconfigured MAC-e PDU.

In the above description, the Node B can allocate the radio resource tothe UE in two ways, via an absolute grant (AG) and a relative grant(RG). The AG indicates an absolute value of a quantity of a radioresource usable by the UE. The RG indicates a variation from a quantityof a radio resource previously used by the UE. Namely, if the UEinitially requests a resource allocation, the Node B allocates the radioresource to the UE using the AG. The UE then preferentially sets aserving grant (SG) to a value of the AG and transmits data in uplinkwithin a range of the value. Thereafter, if it is decided that the SGused by the UE is insufficient by considering a channel status, a UE'sbuffer status, a volume of data to be transmitted and the like, the NodeB sends the RG indicating that the UE can raise the SG by apredetermined quantity. If it is decided that the SG used by the UE isexcessive, the Node B sends the RG indicating that the UE should lowerthe SG by a predetermined quantity. The UE then adjusts the SG based onthe received RG and always uses the radio resource within a rangesmaller than the SG.

An E-DCH transport format combination indicator (E-TFCI) indicatesinformation for a MAC-e PDU transmitted via E-DCH. Specifically, theE-TFCI indicates how much data is being delivered. If a transmittingside differs from a receiving side in making a decision regardinginformation for a transmitted data block, communications cannot beperformed correctly. Hence, the transmitting side transmits informationnecessary for decoding data carried over an enhanced dedicated physicaldata channel (E-DPDCH), such as a size of the MAC-e PDU, each time theMAC-e PDU is transmitted via the E-DCH. As shown in FIG. 5, the MAC-ePDU is physically transmitted via the physical channel E-DPDCH and theE-TFCI is transmitted via an enhanced dedicated physical control channel(E-DPCCH). In the related art, the MAC-e PDU transmitted via E-DPDCH maycontain the data to be transmitted as well as the control information.

The E-DPCCH, which includes information essential to the decoding of thedata carried over the E-DPDCH, is much stronger against errors than theE-DPDCH. Thus, a number of bits carried over the E-DPDCH are set to asmaller amount. Currently, a bit number used for the E-TFCI is 7.Accordingly, it can be known that a size of different MAC-e PDUsdelivered via the E-DCH is 128 (2⁷=128).

A hybrid automatic repeat request (HARQ) scheme is used for E-DCH toraise a probability of transmitted data successfully arriving at areceiving side and to reduce power necessary for the correspondingarrival. Accordingly, under HARQ, raising the probability oftransmission success and reducing necessary power is dependent onfeedback information sent from the receiving side to a transmittingside. Preferably, the feedback information notifies whether the datatransmitted by the transmitting side correctly arrives at the receivingside.

For instance, if a receiving side correctly receives a packet 1transmitted by a transmitting side, such as a UE, via a physicalchannel, the receiving side transmits a reception success signal oracknowledgement (ACK). If the receiving side fails to correctly receivethe packet 1, the receiving side transmits a negative acknowledgement(NACK). Thereafter, the transmitting side transmits new data, i.e., apacket 2 in case that the feedback is ACK with reference to the feedbackhaving been transmitted by the transmitting side. If the feedback isNACK, the transmitting side retransmits the packet 1. In doing so, thetransmitting side attempts a transmission using both of the formerpacket 1 (firstly transmitted) and the latter packet 1 (secondlytransmitted). If this succeeds, the receiving side transmits ACK to thetransmitting side. If this fails, the receiving side transmits NACK tothe transmitting side. When NACK is received by the transmitting side,the transmitting side repeats the above process. In this case, theretransmitted packet 1 should be identical to the former packet 1. Ifnot, the receiving side is unable to recover the data correctly.

However, if the UE continues to stay in an area having a poor channelstatus or if data to be transmitted by the UE is sensitive to deliverydelay, the UE is unable to indefinitely perform the above-explainedretransmission. Therefore, the receiving side informs a UE of a maximumnumber of available transmissions or retransmissions. In case ofreceiving the NACK from the receiving side after having attempted totransmit data as many times as the maximum number of retransmissions,the UE stops attempting the transmission of the corresponding data andattempts a transmission of next data.

In the related art, a UE includes control information, such as itsbuffer capacity, a quantity of power usable for E-DCH and the like in aMAC-e PDU and transmits the MAC-e PDU; however, the HARQ transmissionscheme is used for transmitting the MAC-e PDU. Namely, the MAC-e PDU ishardly delivered by a single transmission. Instead, severalretransmissions are needed until a receiving side correctly receives theMAC-e PDU. Thus, a delivery delay corresponding to each retransmissionoccurs. Accordingly, since information such as a power quantity and abuffer capacity usable by a UE in uplink is frequently changed, theoccurrence of the delivery delay degrades a quality of service felt by auser.

When a user uses a service such as a web page search, a quantity of datatransmitted in uplink is very small. In most cases, uplink data willinclude only one packet. Nonetheless, in accordance with the related artmethod, a UE includes control information for indicating the presence ofdata to be transmitted in uplink in a MAC-e PDU and transmits the MAC-ePDU. A Node B then transmits information indicating a radio resourceallocation. Afterward, the UE transmits the corresponding data inuplink.

However, the related art method has the following problems. First, ittakes a considerable amount of time to exchange control informationbetween the UE and the Node B. Second, in using a MAC-e PDU to sendcontrol information, the MAC-e PDU is transmitted via E-DPDCH. Asmentioned in the foregoing description, E-TFCI should be used totransmit the MAC-e PDU comprising the control information via E-DPCCHbecause of the strength of E-DPCCH against errors. Namely, both theE-DPDCH and the E-DPCCH are used for the transmission of one controlinformation, whereby power is considerably wasted.

SUMMARY OF THE INVENTION

The present invention is directed to communicating control informationin a mobile communication system.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, the presentinvention is embodied in a method for communicating control informationin a mobile communication system, the method comprising transmitting adata block on a first physical channel, wherein the data block comprisescontrol information, and transmitting an indicator having a specificvalue on a second physical channel for indicating the transmission ofthe control information on the first physical channel.

Preferably, the indicator is associated with the data block transmittedon the first physical channel, wherein the indicator indicates a size ofthe data block on the first physical channel. Preferably, the indicatoris an enhanced transmit format combination indicator (E-TFCI), whereinthe specific value comprises an E-TFCI index equaling zero.

Preferably, the first physical channel is an enhanced dedicated physicaldata channel (E-DPDCH) and the second physical channel is an enhanceddedicated physical control channel (E-DPCCH). Preferably, the data blockis a MAC-e PDU.

Preferably, the control information comprises scheduling information,wherein the scheduling information comprises at least one of highestpriority logical channel identifier, total E-DCH buffer status, highestpriority logical channel buffer status, and mobile terminal powerheadroom.

Preferably, the data block comprises only the control information.

In accordance with another embodiment of the present invention, a mobileterminal for communicating control information in a mobile communicationsystem comprises a processor for processing control information to betransmitted and generating a data block, and a transmitter controlled bythe processor for transmitting the data block on a first physicalchannel, wherein the data block comprises the control information,wherein the transmitter transmits an indicator having a specific valueon a second physical channel for indicating the transmission of thecontrol information on the first physical channel.

Preferably, the indicator is associated with the data block transmittedon the first physical channel, wherein the indicator indicates a size ofthe data block on the first physical channel. Preferably, the indicatoris an enhanced transmit format combination indicator (E-TFCI), whereinthe specific value comprises an E-TFCI index equaling zero.

Preferably, the first physical channel is an enhanced dedicated physicaldata channel (E-DPDCH) and the second physical channel is an enhanceddedicated physical control channel (E-DPCCH). Preferably, the data blockis a MAC-e PDU.

Preferably, the control information comprises scheduling information,wherein the scheduling information comprises at least one of highestpriority logical channel identifier, total E-DCH buffer status, highestpriority logical channel buffer status, and mobile terminal powerheadroom.

Preferably, the data block comprises only the control information.

In accordance with another embodiment of the present invention, a methodfor communicating control information in a mobile communication systemcomprises determining whether a specific event has occurred,transmitting an indicator for indicating a size of a data blocktransmitted on a physical channel if it is determined that the specificevent has not occurred, and transmitting the indicator with a specificvalue for indicating the specific event if it is determined that thespecific event has occurred.

In one aspect of the present invention, the specific event occurs whenthe data block comprises only control information. In another aspect ofthe present invention, the specific event occurs when data to betransmitted is received from an upper layer and no resources for thetransmission of the data are available.

Preferably, the indicator is transmitted on a physical channel differentfrom the physical channel through which the data block is transmitted,wherein the indicator is transmitted through an enhanced data physicalcontrol channel (E-DPCCH).

Preferably, the indicator is an enhanced transmit format combinationindicator (E-TFCI), wherein the specific value comprises an E-TFCI indexequaling zero.

Preferably, the data block is transmitted on an enhanced dedicatedphysical data channel (E-DPDCH). Preferably, the data block is a MAC-ePDU.

Preferably, the control information comprises scheduling information,wherein the scheduling information comprises at least one of highestpriority logical channel identifier, total E-DCH buffer status, highestpriority logical channel buffer status, and mobile terminal powerheadroom.

In accordance with another embodiment of the present invention, a mobileterminal for communicating control information in a mobile communicationsystem comprises a processor for determining whether a specific eventhas occurred and generating a data block, and a transmitter controlledby the processor for transmitting an indicator for indicating a size ofthe data block transmitted on a physical channel if it is determinedthat the specific event has not occurred, wherein the transmittertransmits the indicator with a specific value for indicating thespecific event if it is determined that the specific event has occurred.

In one aspect of the present invention, the specific event occurs whenthe data block comprises only control information. In another aspect ofthe present invention, the specific event occurs when the processorreceives data to be transmitted from an upper layer and no resources forthe transmission of the data are available.

Preferably, the indicator is transmitted on a physical channel differentfrom the physical channel through which the data block is transmitted,wherein the indicator is transmitted through an enhanced data physicalcontrol channel (E-DPCCH).

Preferably, the indicator is an enhanced transmit format combinationindicator (E-TFCI), wherein the specific value comprises an E-TFCI indexequaling zero.

Preferably, the data block is transmitted on an enhanced dedicatedphysical data channel (E-DPDCH). Preferably, the data block is a MAC-ePDU.

Preferably, the control information comprises scheduling information,wherein the scheduling information comprises at least one of highestpriority logical channel identifier, total E-DCH buffer status, highestpriority logical channel buffer status, and mobile terminal powerheadroom.

It is to be understood that both the foregoing general description andthe following detailed description of the present invention areexemplary and explanatory and are intended to provide furtherexplanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention. Features, elements, and aspects of the invention that arereferenced by the same numerals in different figures represent the same,equivalent, or similar features, elements, or aspects in accordance withone or more embodiments.

FIG. 1 is a block diagram of a network structure of a universal mobiletelecommunications system (UMTS).

FIG. 2 is an architectural diagram of a radio interface protocol used bythe UMTS.

FIG. 3 is a diagram of a structural example of a dedicated channel (DCH)and an enhanced dedicated channel (E-DCH).

FIG. 4 is a diagram of a protocol for E-DCH.

FIG. 5 illustrates transmitting a data block via an enhanced dedicatedphysical data channel (E-DPDCH) and transmitting an E-DCH transmitformat combination indicator (E-TFCI) via an enhanced dedicated physicalcontrol channel (E-DPCCH) in accordance with the related art.

FIG. 6 illustrates using at least one specific E-TFCI value forinforming a receiving side of a specific situation occurring in atransmitting side, in accordance with one embodiment of the presentinvention.

FIG. 7 illustrates transmitting a data block via E-DPDCH andtransmitting a specific value of E-TFCI via E-DPCCH, in accordance withone embodiment of the present invention.

FIG. 8 is a block diagram of a wireless communication apparatus, inaccordance with one embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention relates to communicating control information in amobile communication system, wherein the control information of a mobileterminal for scheduling an uplink channel may be notified to a networkmore quickly with less power.

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. Wherever possible, the same reference numbers will be usedthroughout the drawings to refer to the same or like parts.

The present invention provides a method for communicating controlinformation for uplink channel scheduling and a method for scheduling anuplink channel. Accordingly, UE control information for scheduling anuplink channel may be notified to a network side more quickly with lesspower.

In accordance with one embodiment of the present invention, specificsituations associated with control information to be transmitted to anetwork from a UE are made to cope with indicators that can identify thespecific situations. Furthermore, the indicators coping with thespecific situations are respectively transmitted via an uplink controlchannel each time each of the situations takes place.

In one aspect of the invention, UE control information for scheduling anuplink channel is notified to a network more quickly with less power.Preferably, this is accomplished using a physical control channel of theUE.

In another aspect of the invention, in case control information a UE hasto send to a network side exists, a specific area of a physical controlchannel is preferably used. In particular, if control information a UEhas to send to a network side exists, a specific value of a specificarea of a physical control channel is preferably used.

In a further aspect of the invention, in case a specific situationassociated with control information for scheduling an uplink channeloccurs, a UE is informed that a specific situation occurs using aspecific area of a physical control channel. Preferably, in case that aspecific situation occurs, a UE uses a specific value of a specific areaof a physical control channel.

Preferably, the physical control channel is an enhanced dedicatedphysical control channel (E-DPCCH) and the specific area of the physicalcontrol channel is an area to which an E-DCH transmit format combinationindicator (E-TFCI) is allocated. Preferably, the control informationcomprises scheduling information. Preferably, the scheduling informationcomprises a buffer capacity of a UE, a quantity of power usable by a UEin uplink (mobile terminal power headroom), total E-DCH buffer status,highest priority logical channel identifier, and highest prioritylogical channel buffer status, for example.

Preferably, the specific situation is a situation where a buffer of theUE is emptied when the UE has transmitted all data the UE has.Preferably, the specific situation includes a case where there is nomore data to be transmitted despite a presence of a radio resourceallocated to the UE, a case where there is no more data to configure anew MAC-e PDU, and a case where a spare space remains in a MAC-e PDUafter a maximum size of the MAC-e PDU allowed by a radio resourceallocated to a UE has been filled with data in a buffer, for example.

Preferably, the specific situation is a situation where data to betransmitted via an uplink channel by a UE is very small in size or canbe configured with a single packet. Preferably, the present specificsituation is a situation where no allocated radio resource is usable bya UE despite a presence of data to be transmitted in uplink and that thedata is very small in size or corresponds to a single packet.

Preferably, the specific situation is a situation where a quantity ofdata to be transmitted via an uplink channel by a UE is smaller than apreset value. Preferably, the specific situation is a situation wherethere is data to be transmitted by a UE in uplink despite a non-presenceof a UE-usable radio resource and that a size of the data is smallerthan the preset value.

Preferably, if a specific situation occurs in a UE and if it isnecessary to notify a network side of the occurrence of the specificsituation, the UE uses a specific value of E-TFCI, such as E-TFCI=0, forexample. Preferably, in accordance with one embodiment of the presentinvention, all available E-TFCI values are not used for indicating asize of a MAC-e PDU. Preferably, at least one value is used forindicating a specific situation occurring in the UE, as shown in FIG. 6.

Referring to FIG. 6, in accordance with one embodiment of the presentinvention, when transmitting user data using a MAC-e PDU via E-DPDCH, aUE uses E-TFCI for indicating a size of the MAC-e PDU. When the MAC-ePDU is not used for transmitting user data, and if a specific situationoccurs in a UE, at least one specific E-TFCI value is used for informinga Node B of the occurrence of the specific situation. For instance, if a7-bit E-TFCI is transmitted via an uplink control channel capable oftransmitting 10-bit of control data per one slot, 2⁷ (=128) E-TFCIcombinations are possible. Accordingly, instead of allocating an E-TFCIto all 128 values, respectively, to indicate a size of the MAC-e PDU, atleast one value is used as an indicator for indicating a specificsituation associated with a UE's control information for uplink channelscheduling.

In accordance with one embodiment of the present invention, when data tobe transmitted to a Node B from a UE is small in size, a specific valueof E-TFCI is transmitted on E-DPCCH to indicate the presence of controlinformation in a MAC-e PDU being transmitted on E-DPDCH, wherein thecontrol information requests a resource allocation for the data to betransmitted. Preferably, as shown in FIG. 7, when E-TFCI=0 is physicallytransmitted via E-DPCCH, the MAC-e PDU comprising the controlinformation is physically transmitted via E-DPDCH. In one aspect of thepresent invention, the MAC-e PDU physically transmitted via E-DPDCHcontains only the control information.

Preferably, in case of receiving an indicator having the same format ofE-TFCI having a specific value, such as E-TFCI=0, a system does notdecode E-DPDCH. Rather, it obtains the specific situation occurring inthe UE and conducts a next operation.

In accordance with one embodiment of the present invention, when a UEnotifies a system that there is a single packet to be transmitted, thesystem does not use a relative grant (RG) rather than an absolute grant(AG). Preferably, when receiving RG despite having no radio resourceallocated to a UE, the UE believes transmitting a single packet isallowed and transmits the single packet. The UE decides that a radioresource having a predetermined value is allocated to itself in thecourse of the packet transmission. After completing the transmission,the UE decides that no radio resource is allocated to itself.

In accordance with another embodiment of the present invention, when theUE informs the network side that there is a single packet to betransmitted in the above process, the network side can allocate a radioresource to the UE using the AG. Preferably, the UE decides that theradio resource allocation is valid while only the single packet istransmitted. Namely, the UE uses the allocated radio resource fortransmitting the single packet only. In doing so, processes not used forthe packet transmission recognize that there was no allocation ofresource. After completing the transmission, the UE decides that noradio resource is allocated to itself.

In one aspect of the present invention, the above process may beregarded as a type of 3GPP random access channel (RACH). Preferably,when there exists data to be transmitted, a UE notifies the existence ofdata to be transmitted to a Node B using a specific E-TFCI value.Accordingly, the Node B permits the UE to use a radio resource via AGand RG. The UE then transmits data to the network using the radioresource.

In another aspect of the invention, instead of using the indicatorhaving the same format of E-TFCI as stated above, preset indicators maybe used when a UE's situation needs to be efficiently indicated to theNode B. Preferably, if necessary, additional indicators may be allocatedfor faster control information transmission. For example, a specificindicator may be allocated for each UE situation. Preferably, when aspecific situation occurs in a UE, the UE transmits an indicatorcorresponding to the specific situation via E-DPCCH.

In a further aspect of the invention, in the above process, theindicator may be lost in a radio section. Therefore, if there is noresponse from a network after the UE has transmitted the indicator, theUE retransmits the indicator again. If the UE transmits a predefinedindicator due to the occurrence of a specific situation in the UE, theUE continues to transmit the indicator during a predetermined timeinterval as many times as a count set by the network. Accordingly, aprobability that the network successfully receives the indicator israised. In the above description, the response of the network indicatesthat a radio resource is allocated to a UE or that the allocated radioresource is completely removed.

As mentioned above, the E-TFCI facilitates indicating a size of theMAC-e PDU. Thus, the more E-TFCIs used for indicating a specificsituation occurring in the UE, the less the number of E-TFCIs used forindicating a size of the MAC-e PDU. To improve this, in accordance withone embodiment of the present invention, the network designates anE-TFCI for transmitting control information to inform the network of aUE's situation and assigns all undesignated E-TFCIs for indicating asize of the MAC-e PDU. Preferably, the UE uses all E-TFCls, except thedesignated E-TFCI, for indicating a size of the MAC-e PDU.

The present invention describes a mobile communication system and isalso applicable to a wireless communication system for a PDA or notebookcomputer provided with a wireless communication function. Terminologiesdescribed in the present invention are not limited to a range of awireless communication system. And, the present invention is applicableto a wireless communication system using different wireless interfacesand physical layers such as TDMA, CDMA, FDMA, etc.

Contents of the present invention can be implemented with software,firmware, hardware or combination of them. In particular, the contentsof the present invention are implemented using hardware logic such ascode, circuit chip and ASIC in hardware or by codes in acomputer-readable storage medium such as a hard disc, a floppy disc anda tape, an optical storage, a ROM and a RAM using a computer programminglanguage.

Codes stored in the computer-readable medium are accessible andexecutable by a processor. The codes implementing the contents of thepresent invention are accessible via a transmission medium or a fileserver on network. In this case, a code-implementing device includes awire transmission medium such as a network transmission line, a wirelesstransmission medium, signaling, wireless signaling, IR signaling and thelike.

FIG. 8 is a block diagram of a wireless communication apparatus 100 suchas a mobile terminal that performs functions of the present invention.

Referring to FIG. 8, a wireless communication apparatus 100 includes aprocessing unit module 110 such as a microprocessor and a digitalprocessor, an RF module 135, a power control module 106, an antenna 140,a battery 155, a display module 115, a keypad 120, a storage module 130such as a ROM, an SRAM, and a flash memory, a speaker 145 and amicrophone 150.

A user inputs command information such as a phone number by pressing abutton or activates voice using the microphone 145. The processing unitmodule 110 receives and processes the command information to perform afunction requested by the user. The processing unit module 110 searchesthe storage module 130 for data necessary for performing the functionand then uses the data. And, the processing unit module 110 enables theuser's command information and the data searched from the storage module130 to be displayed on the display module 115 for user's convenience.

The processing unit module 110 delivers information to the RF module 135to transmit a radio signal including voice communication data. The RFmodule 135 includes a transmitter and a receiver to transmit and receivethe radio signal. The radio signal is finally transmitted or receivedvia the antenna 140. Once receiving the radio signal, the RF module 135converts the radio signal to a baseband frequency to enable theprocessing unit module 110 to process the radio signal. The convertedsignal is delivered via the speaker 145 or as readable information.

The RF module 135 is used in receiving data from a network ortransmitting information measured or generated by the wirelesscommunication apparatus to the network. The storage module 130 is usedin storing the information measured or generated by the wirelesscommunication apparatus. And, the processing unit module 110 isappropriately used for the wireless communication apparatus to receivedata, process the received data and transmit the processed data.

Preferably, the processing unit module 110 is adapted to process controlinformation to be transmitted and generate a data block. The transmitterof the RF module 135 is controlled by the processor unit module 110 fortransmitting the data block on a first physical channel, wherein thedata block comprises the control information. The transmitter is alsoadapted to transmit an indicator having a specific value on a secondphysical channel for indicating the transmission of the controlinformation on the first physical channel.

Preferably, the processing unit module 110 is adapted to determinewhether a specific event has occurred and generate a data block. Thetransmitter of the RF module 135 is controlled by the processing unitmodule 110 for transmitting an indicator for indicating a size of thedata block transmitted on a physical channel if it is determined thatthe specific event has not occurred. The transmitter also transmits theindicator with a specific value for indicating the specific event if itis determined that the specific event has occurred.

Accordingly, the present invention can communicate control informationfor uplink channel scheduling to a network with less power more quickly.

The foregoing embodiments and advantages are merely exemplary and arenot to be construed as limiting the present invention. The presentteaching can be readily applied to other types of apparatuses. Thedescription of the present invention is intended to be illustrative, andnot to limit the scope of the claims. Many alternatives, modifications,and variations will be apparent to those skilled in the art. In theclaims, means-plus-function clauses are intended to cover the structuredescribed herein as performing the recited function and not onlystructural equivalents but also equivalent structures.

What is claimed is:
 1. A method for a receiver to receive controlinformation via a physical control channel from a transmitter in amobile communication system, the method comprising: receiving thecontrol information via the physical control channel from thetransmitter, wherein the control information comprises an indicatorhaving a specific value selected from among a plurality of values,wherein each of the plurality of values, other than the specific value,is predetermined between the transmitter and the receiver to indicateeach size of data to be received via a physical channel associated withthe physical control channel, wherein the indicator having the specificvalue is used to inform the receiver of a specific situation thatoccurred at the transmitter, wherein the specific situation is relatedto a situation where the transmitter has transmitted data via thephysical channel using only a part of available room of the physicalchannel for transmitting data and is unrelated to indicating each sizeof the data to be received via the physical channel by the indicator;and receiving data via the physical channel based on the identifiedsituation.
 2. The method of claim 1, wherein the data is received in aform of a Medium Access Control Protocol Data Unit (MAC PDU).
 3. Themethod of claim 1, wherein the control information further comprises atransmission power related parameter.
 4. A receiving end device forreceiving control information via a physical control channel from atransmitting end device in a mobile communication system, the receivingend device comprising: an RF module including a transmitter and areceiver, wherein the receiver is configured to receive the controlinformation via the physical control channel from the transmitting enddevice, wherein the control information comprises an indicator having aspecific value selected from among a plurality of values, wherein eachof the plurality of values, other than the specific value, ispredetermined between the receiving end device and the transmitting enddevice to indicate each size of data to be received via a physicalchannel associated with the physical control channel, wherein theindicator having the specific value is used to inform the receiving enddevice of a specific situation that occurred at the transmitter, andwherein the specific situation is related to a situation where thetransmitting end device has transmitted data via the physical channelusing only a part of available room of the physical channel fortransmitting data and is unrelated to indicating each size of the datato be received via the physical channel by the indicator; and aprocessing unit module coupled with the RF module, wherein theprocessing unit module is configured to identify that the specificsituation occurred at the transmitter by using the received indicatorhaving the specific value, wherein the processing unit module controlsthe receiver of the RF module to receive data via the physical channelbased on the identified situation.
 5. The receiving end device of claim4, wherein the data is received in a form of a Medium Access ControlProtocol Data Unit (MAC PDU).
 6. The receiving end device of claim 4,wherein the control information further comprises a transmission powerrelated parameter.